Out of desperation I entered /etc/emulationstation directly into the location of FileZilla, and there are the files! They don’t show when you log on at all, and /etc is actually the name of the directory not something you need to substitute!
One step forward, and then one step back as I find the config file and check it, only to find it is correct. Next suggestion, as jsawhi mentioned, is that the rom I have downloaded is the wrong version so time to check it. Found several databases of what can run and what can’t, all show that inavders will run on the version I have and even the file name matches. Yet I still get missing files, but a new line of investigation seems to tell me that I need to fix the files using yet another download.
Raspberry Pi with a box and Logitec F310 controller, and Retropie